Crossing gate



May 28, 1946.

CROS SING GATE Filed Aug. 5, 1942 D. RICHARDS ET AL 3 Sheets-Shet l KEG/227$ jkmezffwf MI-1y 1946- D. RICHARDS ETAL 2,401,275

CRCSSING GATE Filed Aug. 5, 1942 3 Sheets-Sheet 2 156 fzwezoiszxs. Dadg'yi Ez'c/Zaztisi dmzzez 7. 6m:

May 28, 1946.

-R HARDs ET AL CROS S ING GATE Filed Au 5, 1942 5 Sheets-Sheet 3 i972 Z'Zz'c'afaZs. dmez TWZ- y/lllll rllllww u m V Patented May 28, 1946 CROSSING GATE Dwight Richards and Samuel T. Comfort, Harvey, 11]., assignors to The Buda Company, Harvey, 111., a corporation of Illinois Application August 5, 1942, Serial No. 453,628

2 Claims.

a crossing gate which may be set to operate at any desired speed within wide limits.

Another object of ourinvention is to provide a crossing gate which is gravity lowered and wherein the lowering speed may be accurately adjusted over a wide range.

Another object of our invention is to provide a crossing gate having a new and improved control for regulating the rate at which the gate is lowered.

Another object of our invention is to provide a crossing gate which can be installed on either side of its supporting post and which can be readily adapted to swing in either direction.

Another object is to provide a new and improved crossing gate which will swin laterally when struck by an automobile or other vehicle and which will return to normal position after 7 the vehicle has passed.

Other objects and advantages will become apparent as the description proceeds.

In the drawings:

Fig. 1 is a side elevation of a crossing gate embodying our invention, parts being shown in section to illustrate more fully their construction;

Fig. 2 is a view taken on the line 2-2 of Fig. 1;

Fig. 3 is an irregular horizontal section taken on the line 3-3 of Fig. 2;

Fig. 4 is a vertical section taken on the line 44 of Fig. 2; and

Fig. 5 is a wiring diagram showing the control circuits.

Referring to the drawings, it will be seen that we have illustrated our invention as being embodied in a crossing gate comprising a supporting post l0 carrying a pair of track members l2 and I 4 bolted together and forming an inclined V-shaped track for a roller attached to the base of a housing l8 which carries the gate arm and gate arm operating mechanism. The housing has a pair of rearward extensions and 22 carrying rollers 24 and 26 which bear against the supporting post ID. A pair of rods 28 and 30 is mounted in each rearward extension 20 or 22 and a casting 32 is bolted or otherwise secured to the ends of each pair of rods and carries a second pair of rollers 34 and 36. From the foregoing, it will be apparent that the weight of the housing I8 rests entirely upon the track provided by the track members 12 and I4 and that the movement of the housing along this track is guided by the rollers 24, 26, 34 and 35 which permit the housing to swing about its supporting post Ill.

An electrical motor 38 is mounted in a compartment 43 provided in the housing 18 and drives a motor shaft 42 carrying a pinion 44 and a ratchet wheel 45. The pinion 44 drives gear as integral with a sleeve 50 having pinion 52 formed thereon, The sleeve 50 is rotatably mounted by needle bearings 54 and 56 on a supporting rod 58 mounted in housing walls 60 and Pinion 52 drives large gear 64 keyed to a sleeve 55 rotatably mounted by needle bearings 68 and in on a second supporting rod 12 mounted in wall 62 and an oiiset bracket 74 integral with partition wall 68. Pinion 16 is formed on sleeve 66 and drives gear 18. Gear 18 is keyed to sleeve Bil which is rotatably mounted on rod 56 by needle bearings 82, 84 and 86.

Pinion 88 is formed on sleeve and drives segment gear 9!] keyed to gate arm shaft 92 (Fig. 1). As best shown in Figs. 2 and 3, gate arm shaft 92 is rotatably supported by needle bearings 94 carried in bearing members 95 and 98, integral with housing walls it!!! and B2, respectively. The gate arm shaft 92 has directly mounted thereon side members 102 and I04 of the gate arm which may be provided with any suitable counterweights in accordance with the usual custom.

The gate arm is adapted to be lowered by gravity and we have provided a special mechanism for controlling the rate to which this gate arm is lowered. This mechanism is best shown in Fig. 1 and comprises a dashpot cylinder IDS having a reciprocal piston I98 attached to a piston rod H0 passing through a suitable packing gland H2 formed in the cylinder head H4. The upper end of the piston rod is connected by pivot H6 to an arm H8 attached to the segment gear 99. The piston I08 is provided with check valves I20 which permit substantially free flow of fluid through the piston during its upward stroke, i. e., while the gate arm is being raised under the power of the motor 38.

The dashpot cylinder I06 is supported on pivot pins I22 mounted in bosses I24 provided by the housing I8 so that the cylinder I86 may automatically adjust itself to the position of the piston rod IIO as arm H8 and sector gear 96 rotate with gate arm shaft 92. Dashpot cylinder Illfi is provided with a fixed port I26 permitting relatively free flow of fluid therethrough between the cylinder Its and a bypass passageway I28. A plurality of spaced ports I30, I32, I34 and'I3'6 are spaced lengthwise of the cylinder I06 and also connect this cylinder with the bypass passageway I28. These latter ports are controlled by needle valves I38, I40, I42 and I44, respectively, and these needle valves may be independently adjusted to provide any desired rate of descent for the gate arm.

When the gate arm is atits extreme upward position, as indicated in Fig. l of the drawings, the segment gear an engages a resilient stop 146 and when the gate arm is in the down or hori- Zontal position, the other end of this segment gear 90 engages ;a second resilient .sto-p I48. These stops are adjustable to provide anydesired variationszin travel of-the-gate armand different strength springs may be-substituted in these stops :to adapt them for use with gate arms of widely varying weights.

'InvFig. 1 of the ;drawings, the main portion of the gate arm extends to --,the--left-of housing It when'the gate-arm is-inhorizontal-position. If

it is desired to mount the gate arm'on the shaft .32..so that the main portion ofthegate arm extends 'to the right of this housing, the .dashpot cylinder Ir-06 is shifted so that its supportin pivot changes'the gate arm can-be adaptedto extend either to the right or left of the housing I8 and this housingcan be mountedon either side of supporting post I for either direction ofoperationof the gate arm. This is particularly advantageous where our improved crossing gate is mounted onlalsupport which has heretofore been in .use, since-it :permitsour crossing-gate to be installed without interfering with signal lights and other signal mechanism theretofore in use.

lt is desirable to provide means whereby the operating mechanism.maybe lubricated at periodic intervalsand-the means which we have provided to'accomplish this result is best shown in Fig. 3. In this figure the .g-atearm shaft 92 is illustrated as being provided with a A lubricant receiving fitting l54communioating withducts I55 and I-EiB-leadingtothe needle bearingf94. It will .be understood that similar .meansmay be provided for lubricating the needle bearingat the other end of this shaft. Similarly, rods Ii.and I2 are .illustratedas beingprovided with lubricant receiving fittings. I 60 and -I 62, respectively, and it will .be .understood -by those skilled in the .art

that these rods. are provided with suitable ducts not shownforconductingthis lubricant :tothe various needle bearingsmounted on these shafts.

The-gate-arm is held in verticalpositionhy a s ring pressed latch I64 mounted on an arm I 58 pivoted at-I'IIJ .to.partition .-6!!. A link I'l'2 connects thearm 468 with the arm I14 of .a bell controls-are enclosed in the housing I6.

bell crank lever I16 and co-acts with a pair of holding coils I85.

As shown in the wiring diagram (Fig. 5) the motor 38 is in a circuit which is opened and closed by a control relay I88 and including an overload thermal relay IS!) which is inactive during the normal operation of the crossing gate. A second circuit i in parallel with the motor 38 and includes a limit switch I92 and pull-up coils I82.

The control relay I88 has a coil I94 located in a circuit which includes a limit switch I96 and track relay I98 and a circuit containing the hold-- switch we. The track relay I98 has a coil 20!! which is connected to the rails of the railroad track and is energized by the track circuit.

The limit switches I92 and IE6 are preferably mercury switches which are opened or closed by tilting. These switches are independently mounted on the gate arm shaft 92, as indicated at A in Fig. 4c. and each switch may be independently adjusted so that these switches open or close at any desired positions of the gate am.

All of the operating mechanism and switch This housing is provided with a hinged door 262 which is normally held in closed position by a latch 204. A padlock may be attached-to the staple .206 to prevent unauthorized persons from opening the door 262 and tampering with the gate operating mechanism; We shall now describe the operation of our newand improvedcro'ssing gate.

When the gate is:in normal or raised position. current flowing in the track circuit energizes coillilfiand holds relay I98 .in closed position. This maintains closed the circuit to the holdin coilsv I 86 and these coils hold latch -I Min engagement with the ratchet wheel -46 and thus prevent the gate arm from falling under the force of gravity. In this position of the parts, .limit switches I92 and IE6 and control relay ISIS-are. in the position shown in Fig. 5.

When an approaching train hort circuit the track, circuit relay 1S3 drops and breaks the circuit leading to holding coils I85. The-resulting de-energization of these coils permits pawl I64 to moveaway from ratchet wheeltaunder the influence of gravity-acting upon this .pawl and its associated parts-and under the force exerted by the ratchetwheel under the .gate arm load. Thereupon the gate armstarts to lower under the force of gravity acting thereon.

While the force tending to-lower the gate arm decreases as this gate arm approache .horizontal position, the result would stilLbe a-continued increase in the. speed of descent of the gate arm unless some control .means were provided to check this descent. In our improved crossing gate Weaccurately control this-rate of'descent by the dashpot cylindeyA-OB and its associated mechanism. When the g te a p are at the upper end of their movement, that part of the cylinder Ifilfiwhich igbeneaththe-piston is in substantially free communication with the-bypass I28, but the upperendof thisbypass communicates with the upper end of cylinder Iiifithrough only the single-port. I 3% which greatly restricts flow of thelow temperature .011 from the bypass to the upperend oft-the cylinderand thus retards downward movement of the piston I98 and the gate arm connected therewith.

A the piston moves further downin the cylinder I95, the piston reaches a point Where it is below port I34 and'this port cooperatesin returning fluid to that part of the cylinder above the piston, thereby decreasing the resistance to the descent of the piston. As the piston passes below port I32, the resistance to its descent is further decreased. Preferably these decreases in resistance correspond to decreases in torque exerted by the gate arm and serve to maintain a substantially constant speed of descent of the gate arm and piston. Port I25 provides relatively free flow of fluid between the cylinder B66 and bypass I28 and as soon as a piston passes below this port its rate of descent is materially reduced by reason of the fact that all fluid below the piston must pass from the cylinder to the bypass through restricted port I36. This lower port I36 thus controls the cushioning ef fect of the dashpot and this cushioning effect can be varied by adjusting the needle valve 533. Similarly the first part of the downward movement of the gate arm can be adjustably controlled by adjusting needle valves M6, M2 and EM so that any desired rate of descent can be obtained.

It is usual to provide lights, bells and similar signal mechanism to cooperate with the crossing gates in warning pedestrians and vehicle operators of the approach of trains. Such signal mechanisms are commonly controlled by the position of the gate arm and with our new and improved crossing gate this can be easily accomplished by mounting the control switches on the gate arm shaft 92 so that such signal means will be set in operation as the gate arm descends and turned off as the gate arm is raised. Our cross" ing gate, however, is not limited to such control of the signaling mechanism and any other usual or suitable manner of controlling this mechanism may be provided.

A the gate arm descends, limit switch I62 is opened and remains open until the gate arm again approaches the upper limit of its movement. Opening of this limit switch produces no effect, since the circuit of which it forms a part remains broken, as shown in Fig. 5.

After the gate arm through an angle of approximately 5, limit switch I96 closes and remains closed until the gate arm is again raised to within approximately 5 of it upper limit of movement. This likewise produces no effect, since the circuit of which this limit switch forms a part is broken by track relay I98.

After the train has passed, coil 2G6 is again energized by the track circuit and closes the track relay I98, thereby energizing holding coil 5% and control relay I86. The holding coils i536 are too weak to raise pawl I64 into engagement with ratchet wheel 45 and thus the energization of these coils is without effect. The energization of control relay I88, however, closes the motor circuit and motor 38 is energized and starts raising the gate arm.

The speed at which the gate arm is raised will depend upon the angle through which thi gate arm must be raised, the speed at which the motor operates, and the particular sizes of gears and pinions which are interposed between the motor and gate arm. With a motor operating at a conventional speed, such as 1725 R. P. M., the speed of raising the gate arm may be varied from 4 seconds to 8 seconds for a 90 movement by simply changing the size of the motor pinion gear 44 within permissible limits. This variation in rate of lift of the gate arm is sufficient to meet practically all conditions, but special is moved downward conditions may be provided for by using a motor having a different operating speed or by using different sized gears in the gear train connecting the motor pinion with the gate arm shaft.

During the upper movement of the gate arm, oil'in that part of the dashpot cylinder which is above the piston I08 fioWs freely through the check valves I26, provided in this piston, and offers substantially no resistance to the upward movement of the piston. As the gate arm reaches a position approximatel 10 before its upper limit of movement, limit switch I92 closes, thereby energizing pull-up coils I 82. These coils are powerful coils of relatively low resistance and cooperate with the relatively weak holding coils its. to pull the pawl 64 into engagement with the ratchet wheel 46. This brings the pawl I66 into engagement with ratchet wheel while this wheel is still rotating, but the resilient mounting of the pawl I64 prevents injury to pawl I64 when it is brought into engagement with the rotating wheel.

Just before the gate arm reaches the upper limit of its movement, limit switch I96 opens, thereby de-energizing control rela I86, whereupon this relay breaks the circuit to the motor 38 and pull-up coils I 82. Holding coils I 86, however, remain energized and have sufficient strength to maintain pawl I 64 in engagement with ratchet wheel 46 so that no retrograde movement of the wheel or corresponding downward movement of the gate arm may occur. The holding coils are of high resistance and require but an exceedingly small current which creates no appreciable drain on the battery or other source of current supply for the gate operating mechanism.

If the gate arm is struck by an automobile or other vehicle while in lowered position, the gate arm and housing I8 containing the operating and control mechanism can swing as a unit about the supporting post I 0 and by thus yielding with the impact avoid injury to the gate arm and its associated mechanism. As the gate arm and housing swing about the post I6, roller I6 rides up one side of the inclined track provided by the members I2 and I4 mounted on the post. The lateral swinging of the gate arm and its operating mechanism is resisted by the action of gravity so that the lateral movement of this arm is no greater than is necessary to permit the gate to accommodate the movement of the vehicle and as soon as the vehicle has passed the gate arm returns automatically to normal position transversely of the highway.

When it is desired to paint or repair the gate arm, it is usually desirable to have the gate arm in lowered position but undesirable to have the gate arm extending across the highway while the painting or repair is being effected. We have, therefore, provided the track for the roller I6 with a retaining notch ZID so that prior to making the repair the gate arm can be swung until the roller I6 engages and is held in this notch. In this position the gate arm will extend parallel to the highway and not interfere with trafiic along the highway. After the repair has been completed a slight lateral push on the gate arm will cause the roller I6 to roll down the track to the position shown in Fig. 1.

In most installations it is desirable to mount the gate arm so that it will swing laterally if struck by an automobile or other vehicle and we have illustrated and described a preferred embodiment of our invention as being mounted to provide such lateral swinging movement, .In some installations, however, such lateral swinging movement is'not necessary or desirable and in these latter installations the track J4 and rollers-l6, '24, 26, 34 and 36 can be eliminated and the housing i8 rigidly and firmly secured to the supporting post H1.

The particular crossing gate which we have illustrated and described has been designed to fulfill :the needs of a totally automatic gate. While this gate is designed to lower by gravity, power lowering can be provided by installing an instantly reversible motor, together with the necessary control equipment which is readily available on the open market. This change would not destroy the abilit of the gate to lower by gravity-and would be of advantage in only a few special installations which were intended to satisfy unusual conditions.

While We have illustrated and described only a single embodiment of our invention, it will be understood that our invention may assume numerousforms and that the scope of our invention is defined by the following claims.

W e claim:

1. In a crossing gate of the class'described, the combination of a gate arm movable in a vertical plane, power operated means for raising said gate arm, said gate arm being adapted to descend under the force of gravity, a housing for said power operated means, a supporting post for said housing, and reversible control means for regulating the descent of said gate arm and permitting the main portion of said gate arm to extend in either direction from said housing, said reversible control means including a dashpot cylinder, a pair of pivotal mountings therefor, a piston reciprocable in said cylinder, a piston rod attached to said piston, and a segment gear attached to said gate arm and having means at each end thereof for attachment to said piston rod.

2. In a crossing gate of the class described, the combination of a gate arm movable in a vertical plane, means for raising and lowering said gate arm and permitting the main portion of said gate arm to extend in either horizontal direction, reversible control means including a dashpot cylinder, a pair of pivotal mountings therefor, a piston reciprocable in said cylinder, a piston rod attached to said piston, and a segment gear attached to said gate arm and having means at each end thereof for attachment to said piston rod.

DWIGHT RICHARDS. SAMUEL T. COMFORT. 

